I recently got a condo unit (low rise condo) on the 4th (top) floor. The unit previously had a gas water heater but was replaced with an electric unit after the gas one broke down I suppose. This was before I got it.

I didn't realize the issues I'd be facing. The electric bills are too high. I thought of going back to gas water heater and asked the heater vendor to do an analysis. But, they refused saying that vent has a black pipe which needs to be changed to White PVC pipe and vent cannot be run through the unit.

Now, I am not sure what to do and the management is not willing to fix it for me. What can I do?

Thanks Jimmy, Zhentar and Comintern for your answers,

The hot water tank is also used to heat the unit during the winter times, this is what raising the electricity bills. And one more thing hurting is the Gas cost is covered by the maintenance bill and i am not using gas in this unit as the water heater is electricity, so i end up paying both the gas bill and electricity. And the other units in the building are having gas water heater.

3 Answers 3


Only "power-vent" type gas water heaters can be vented with plastic pipe. These are gas water heaters with a fan on top which blows the flue gas (and cools it by mixing surrounding cool air with it, hence plastic vent is OK) out of the house. Most can be vented with 3" PVC (white), ABS (black), or CPVC (kinda tan colored). These vents can be run horizontally and can have 90 degree bends (limits on that though, see instructions/local code). So if the black pipe in question is plastic, it is probably ABS, and the vendor might be wrong.

Not sure if you know what you are getting into, direct-vent heaters are significantly more $$ than regular natural draft gas heaters (which require metal vent pipes that go more or less UP only). Some of these direct-vent heaters now require a fresh air supply from outside because they have sealed burners, you may not be equipped for that. You would need to be 100% sure of the condition, length, and route of the existing vent if you use it. Then there is the piping for water and gas and such, labor...

It might not be worth the trouble and expense to change back. Amortize the cost of the new heater over time and I am not sure it would pay off.


Jimmy's answer covers gas water heaters pretty well. But there are two other points I'd like to address in regards to "what can I do?"

  • Heat Pump Water Heaters are electric water heaters with significantly higher efficiency than normal resistance water heaters, generally rated in the range of 200% to 275% efficiency.

  • Reducing your hot water usage can be easier and more effective at reducing your water heating cost. Average usage estimates for a small family at average electricity prices is somewhere in the range of $50/month, and it's not hard to hit half that if you're conscious about conserving hot water.

Also, are you sure it's your water heating cost that's driving your electricity bill? Without any context, I don't have much to speculate on what might be the problem, but water heating generally wouldn't be my first suspect.

  • I think you're confusing Energy Factor (EF) with efficiency percentages. A 200% efficient hot water heater could produce more electricity by heating water than it used. The correct range would be EFs between 2.00 to 2.75
    – Comintern
    Aug 6, 2014 at 23:25
  • @Comintern: Depending upon climate, a heat pump may be able to use 1000 BTU (0.293kWH) worth of of electricity to extract 1000 BTU of heat from the outside environment, supplying 2000 BTU of heat to the intended application. Since outside heat is "free", heat pumps can thus be over 100% efficient. Indeed, since a simple resistive heater is 100% efficient, heat pumps would be pointless if they couldn't achieve better-than-100% efficiency.
    – supercat
    Feb 21, 2015 at 19:01

If your heater is on a 'exterior wall' consider direct-vent outside, by-passing the flue stack. Another option can be installing a heater on a balcony so there's little need of flue handle and in case of leak you won't destroy all your house. In case of ice it'll be also super-cheap to replace (for 200€ you ca get an acceptable machine) like this: tankless water heater

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